1. Field of the Invention
The present invention relates to a direct weaving apparatus comprising, in combination, a loom, and a weft yarn processing machine for processing yarns and for directly feeding processed weft yarns to the loom and, more particularly, to a method of operating a direct weaving apparatus provided with yarn storage drums.
2. Prior Art
An ordinary loom is not provided with any weft yarn processing machine and weft yarns are processed by weft yarn processing processes separate from a weaving process. Weft yarn processing processes process yarns to produce various weft yarns; for example, weft yarn processing processes twists filament yarns to produce nonstretch textured yarns (Taslan.RTM. yarns) or entangled yarns, dye yarns, false-twist yarns or double yarns. Yarn packages of the weft yarns thus processed are supplied to the loom. Since the yarn is difficult to be unwound from the yarn package thus produced by the weft yarn processing process separate from the weaving process, only limited kinds of processed yarns can be used as weft yarns on the loom. Furthermore, weft yarn packages produced by the weft yarn processing process separate from the weaving process require a winding operation for winding processed weft yarns in yarn packages and the transportation of weft yarn packages from the winding process to the weaving process. Such a method of supplying weft yarn packages to the weaving process is unable to deal with fabric production in a multiproduct small-lot short cycle production system. To deal with fabric production in a multiproduct small-lot short cycle production system, there has been proposed a direct weaving apparatus comprising, in combination, a loom and a weft yarn processing machine and capable of carrying out various weft yarn processing processes and of omitting operations for winding weft yarns in weft yarn packages and the transportation of weft yarn packages.
A weft yarn processing machine is installed beside a loom to feed a weft yarn. The weft yarn processed within the weft yarn processing machine is supplied to a jet nozzle of the loom. A gripper and the jet nozzle are controlled in synchronism with the operation of the loom. A length of the weft yarn is retained in a yarn retaining pipe while the gripper is closed. The gripper is opened and compressed air is supplied to the jet nozzle to insert the weft yarn retained in the yarn retaining pipe, by the jet nozzle.
The direct weaving apparatus retains the weft yarn Y in a free state in the yarn retaining pipe while the gripper is closed. Therefore, it is feared that a highly textured entangled yarn or a Taslan yarn is snarled in the yarn retaining pipe. Accordingly, it is preferable to use a known yarn storage drum instead of the yarn retaining pipe. However, it is feared that an incompletely textured weft yarn is fed after the start of the weft yarn processing machine until the mode of operation of the weft yarn processing machine reaches a steady state. Accordingly, defects will be formed in the fabric in the initial stage of weaving operation if the weft yarn processing machine and the loom are started simultaneously and hence the waste suction pipe is necessary. There has not been proposed any method of starting a direct weaving apparatus provided with yarn storage drums, capable of timely removal of waste yarns.